\Zir"con\, n. [F., the same word as jargon. See {Jargon}
a variety of zircon.] (Min.)
A mineral occurring in tetragonal crystals, usually of a
brown or gray color. It consists of silica and zirconia. A
red variety, used as a gem, is called {hyacinth}. Colorless,
pale-yellow or smoky-brown varieties from Ceylon are called
{jargon}.
{Zircon syenite}, a coarse-grained syenite containing zircon
   crystals and often also el[ae]olite. It is largely
   developed in Southern Norway.